The exudate from the preen (or uropygial) gland found at the base of the tail of most birds, is applied to the plumage during preening. Preen gland exudate has a lipid fraction and a non-lipid fraction containing proteins, inorganic salts and cell fragments. The lipid fraction (herein referred to as preen oil) is made up of monoester, diester and triester waxes (long-chain carbon molecules which contain one, two or three ester bonds). Preen oil isolated from turkey preen glands has been shown, for example, to include the fatty acids C10:0, C12:0, C14:0, C16:0, C17:0, C18:0, C19:0 and C20:0. In vitro assays have suggested that C19:0 (19:0 or nonadecanoic acid) has possible anti-inflammatory, anti-tumor, and proliferous cell inhibitory effects.
There is increasing interest in natural substances that have health benefits in medicine and animal agriculture. Preen glands are included in segregated tissue from animal processing (STFAP). Currently, STFAP is discarded or rendered with other wastes during meat harvest and processing, and can be separated from a larger stream of waste and by-products. The oil from the animal tissue can be easily removed through mechanical means (dissection) and extracted using solvents. It is thus desirable to isolate preen oil from preen glands that would otherwise be part of the waste stream of animal processing and to identify uses for the purified preen oil.
What is needed are methods of use of natural substances such as preen oil to provide health benefits in humans and animals.